In a conventional electrophotographic image forming apparatus using the electrophotographic image forming process, a process cartridge type in which an electrophotographic photosensitive member and process means actable on the photosensitive member are integrally assembled into a cartridge and this cartridge is detachably mountable to a main assembly of the electrophotographic image forming apparatus is employed.
In such a process cartridge, as shown in FIG. 25, an opening provided to a developer accommodating container 100 for accommodating the developer (toner, carrier, etc.) is sealed with a sealing member 101 constituted by a seal member or the like. Further, a type in which a bonded portion 102 of the sealing member 101 is pulled and peeled during use, thus unsealing the opening to enable supply of the developer has been widely employed (Japanese Laid-Open Patent Application (JP-A) Hei 4-66980).
Further, against a problem such that the developer is scattered in the process cartridge in a developer filling step during manufacturing of the process cartridge, a constitution in which the developer accommodating container 100 is made deformable has been devised (JP-A Hei 4-66980).